Improvement in naval architecture



UNITED' STATES Aram OFFICE.

I JOHN BOWDLEAR, OF ROXBURY, MASSACHUSETTS.

IMPROVEMENT IN NAVAL ARCHITECTURE.

Specification forming part of Letters Patent N0. 40,3 2 l dated October 20, 1863; antedated October 14, 1863 T0 all whom it 71mg concern.-

Be it known that I, JOHN BOWDLEAR, of Roxbury, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in the Oonstiuction ot' Vessels; and I do hereby declare that the following description, taken in connection with the accompanying drawings, hereinafter referred to, forms a full and exact specification of the same, wherein I have set forth the nature and principles of my said improvements by which my invention may be distinguished from all others of a similar class, together with such parts as I claim and desire to have secured to me by Letters Patent.

In the construction of vessels it is evident that speed and steadiness are two ofthe most essential requisites to be attained. It is also manifest that great speed cannot be arrived at in vessels of large carrying capacity or great breadth of beam, and to diminish bread th of beam is to sacrifice steadiness of motion in almost exact proportion to the diminution. Many attempts then have been made in naval architecture to combine in a vessel the qualities of rapid sailing and stiffness, so as to prevent rolling and pitching. In maturing the present invention I have endeavored to secure these desiderata, and after many experiments, and with a full knowledge of what steps have been previously taken to achieve thedesired results, and the reasons which have caused their failure or but partial attainment, have succeeded in producing` a new system of construction which meets the requirements so long aimed at. The methods heretofore employed for producing stiffness 77have been various. Thus, for instance,t-wo bilge-keels have been used, as well as a series of keels placed upon a ships bottom. The outer surface of a vessel below the water-line has also been covered with comparatively slight corrugations or furrows, with a view to producing the same result. My invention goes beyond these methods, which are but approximations to the desired construction; and consists in forming the vessel below the water line of a series of peculiarly-formed deepgrooves or channels and projecting ridges or folds, and in combination with the same constructing the ribs of the vessel in a peculiar manner with a view to tit and receive the outer covering and serve as a firm bearing thereto, and to increase their strength. The channels or grooves I construct of a peculiar form in such a manner that they are undercut or wider at the bottom, or part nearest the body of the vessel, than at their ou ter edges, and so that they shall taper from amidships to the stem and stern, respectively.

In the accompanying plate of drawings, Figure l is a side View ot'a vessel made according to my improvements, and Fig. 2 a central transverse section of the same.

a a, Src., represent a series of grooves or channels, and b b, 85e., a series of ridges or folds extending from about the water-line to the keel c of the vessel. The grooves a a are peculiarly formed, being wider at the part marked d than at the top, (marked 6,) as shown in Fig. 2. It will be observed that this form I of groove will have a peculiar hold upon the water and prevent the latter from being easily displaced in a lateral direction. Thusthe vessel will constantly have a reacting body of water to press against when it has a tendency to careen or roll, and will therefore be remarkably stiff and able to sail much nearer the wind than vessels of ordinary construction. This result is but imperfectly accomplished in the case where a series of straight keels is used, or even where ordinary regular shallow corrugations are employed, because the water between such straight keels or corrugations cannot be retained therein, but will readily slip by them and be displaced therefrom in a lateral direction, yielding in fact to the sidewise motion of the vessel. In the present instance the water cannot easily be laterally displaced from the grooves or channels on account of their peculiar shape in. cross section, as will readily be manifest. The grooves or channels a a are tapered from a point amidships each way to the stem and stern, respectively, so as to prevent as little impediment to the passage of the water through them longitudinally as possible. The ribs 71J h, &c., of the vessel are formed of a peculiar shape, as shown in the drawings-viz., with a continuous curved portion, j', and a series of projecting folds, gg, &c. This forms a remarkably strong backing to the sheathing or covering when put on in respective folds and grooves, and not only strengthens the ribs themselves, but renders my peculiar sheathing more readily applied and fastened. It will be obvious that the projecting 'olds g (1, &e., may he made hollow and furnished with an apparatus for allowing the external water to enter them for the purpose of sinking the vessel to any desired level in case of an engagement, as Well as suitable devices to relieve them oi" Water when desired.

Having thus described my improvement, what I claim as my invention, and desire to have secured to me by Letters Patent, is-

l. The constructing a ships bottom With the series of peculiarly-shaped grooves or channels 

